Method for Regenerating Adsorber and Dialysis System

ABSTRACT

A method for regenerating an adsorber which has a porous body and does not have an enzyme includes a dialysis step, in which the adsorber is connected to a dialysate circulation unit to cause uremic substances within a dialysate to be adsorbed onto the adsorber, and a regenerating step, in which the uremic substances which are adsorbed on the adsorber are desorbed by regenerating water that flows in a regenerating water flow unit. A dialysis system is equipped with the dialysate circulation unit, the adsorber, which is connected to the dialysate circulation unit, and the regenerating water flow unit. The regenerating water flow unit is connectable to the adsorber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/768,008 filed May 28, 2020, which is the United States national phaseof International Application No. PCT/JP2018/043600 filed Nov. 27, 2018,and claims priority to Japanese Patent Application No. 2017-228862 filedNov. 29, 2017, the disclosures of which are hereby incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure is related to a method for regenerating anadsorber and a dialysis system.

Description of Related Art

Conventionally, there is a method for removing harmful substances from ablood filtrate in an ultrafiltration type blood purification apparatus.

The method for removing harmful substances employs two or more adsorberswhich are filled with nitrogen containing fibrous activated carbonadsorbent alternately or in a predetermined order to adsorb harmfulsubstances with one or more adsorbers. Harmful substances are desorbed(regeneration of the adsorber) from the one or more adsorbers which haveadsorbed the harmful substances and are not currently being utilized foradsorption. That is, adsorption of the harmful substances by theadsorbers and desorption of the harmful substances from the adsorbersare alternately conducted during treatment in which a patient's blood iscirculated through an ultrafiltration membrane refer to JapaneseExamined Application Publication No. S64-9029).

SUMMARY OF THE INVENTION

The method for removing harmful substances from adsorbers in aconventional conventional blood purification apparatus requires a largeand complex apparatus, and it is difficult to change the installationlocation of such a blood purification apparatus.

According to one aspect of the present disclosure, a method forregenerating an adsorber, which has a porous body and does not have anenzyme, is provided. The method for regenerating an adsorber includes:

a dialysis step in which the adsorber is connected to a dialysatecirculation unit to adsorb uremic substances in a dialysate onto theadsorber; and

a regenerating step following the dialysis step, in which the uremicsubstances which are adsorbed onto the adsorber are removed byregenerating water that flows in a regenerating water flow unit.

According to the present disclosure, it is possible to provide a methodfor regenerating an adsorber and a dialysis system that facilitateschanging installation locations of a blood purification apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram for explaining a dialysis system according to afirst embodiment during treatment.

FIG. 1B is a diagram for explaining the dialysis system according to thefirst embodiment during regeneration.

FIG. 2A is a diagram for explaining a dialysis system according to asecond embodiment during treatment.

FIG. 2B is a diagram for explaining the dialysis system according to thesecond embodiment during regeneration.

FIG. 3 is a graph that shows the results of a urea electrolysis test.

DESCRIPTION OF THE INVENTION

Hereinafter, embodiments will be described in detail with reference tothe attached drawings.

Hereinafter, a first aspect (hereinafter, referred to as “firstembodiment”) will be described in detail with reference to the drawings.Note that the same elements will be denoted by the same referencenumbers or reference symbols throughout the entirety of the descriptionof the embodiments. Note that in the following description, unlessotherwise specified, the term “treatment” refers to a state in which theblood of a patient 200 is being circulated through a dialyzer 30 in ablood circulation unit 10, and the term “regeneration” refers to a statein which the blood of the patient 200 is not being circulated in theblood circulation unit 10. Note that although the present embodimentshows an example applied to hemodialysis, the present disclosure is notlimited to such a configuration. The present disclosure may be appliedto all blood purification treatments such as hemofiltration andhemofiltration dialysis. Note that in the following description, theterm “dialysis” refers to dialysis treatment.

FIG. 1A is a diagram for explaining a dialysis system 100 according to afirst embodiment during treatment, and FIG. 1B is a diagram forexplaining the dialysis system 100 according to the first embodimentduring regeneration.

(Dialysis System)

The dialysis system 100 according to the first embodiment is a bloodpurification apparatus for performing hemodialysis treatment. Thedialysis system 100 performs hemodialysis by guiding the blood of thepatient 200 to the dialyzer 30, which is external of the patient's body,and returning purified blood to the body of the patient 200.

In greater detail, the dialysis system 100 is equipped with a dialysatecirculation unit 20 which is connected to the blood circulation unit 10via the dialyzer 30, an adsorber 40 (adsorption column) having a porousbody, and a regenerating water flow unit 50, as illustrated in FIG. 1Aand FIG. 1B.

The blood circulation unit 10 is a component for circulating bloodbetween a shunt 210 which is applied to the body of the patient 200 andthe dialyzer 30 which is provided external of the body of the patient200. The blood circulation unit 10 includes an arterial blood circuit 12and a venous blood circuit 13 that connect the dialyzer 30 to the shunt210 via a first connection unit 11. In addition, functional units suchas a blood pump, a supplemental fluid supply line, an anticoagulantinjection unit, an air trap chamber, a measuring instrument, and amonitoring device, which are not illustrated, are provided in the bloodcirculation unit 10 as appropriate.

The dialyzer 30 is an artificial kidney that purifies the blood of thepatient 200 by exchanging substances between the blood of the patient200 and a dialysate through the operations of diffusion and filtrationthrough a semipermeable membrane. The dialyzer 30 is, for example, thatin which a plurality of fine tubes formed by a semipermeable membrane,through which the blood of the patient 200 passes, are covered with acylindrical body through which the dialysate passes, as a component ofthe dialysate circulation unit 20.

The dialysate circulation unit 20 is a component for circulating thedialysate between the dialyzer 30 and the adsorber 40. The dialysatecirculation section 20 includes dialysate circuits 21 and 22 thatconnect the adsorber 40 to the dialyzer 30 via a third connection (notillustrated). In addition, functional units such as a dialysate pump, adialysate supply line, a balance chamber, a heater, a drainage line, ameasuring device, a monitoring device, and a dialysate controlapparatus, which are not illustrated, are provided in the dialysatecirculation unit 20 as appropriate.

The adsorber 40 includes a porous body which is capable of directlyadsorbing uremic substances. That is, the adsorber 40 is an adsorberthat can directly adsorb uremic substances. Accordingly, in the presentembodiment, it is not practically necessary for the adsorber 40 to havean enzyme for decomposing urea, such as urease. Accordingly, in thepresent specification, the “adsorber 40 not having an enzyme” means thatthe adsorber 40 is practically free of an enzyme for decomposing urea.The expression “practically free of an enzyme for decomposing urea”means that an aspect that contains an enzyme for decomposing urea in anamount that does not practically function (for example, if an amount ofurea which is adsorbed by the porous body is designated as X [g] and theamount of urea decomposed by an enzyme is designated as Y [g], theaspect is that in which Y/(X+Y)≤0.1) is not excluded. Note that in thefollowing, it is assumed that the adsorber 40 does not contain anyenzymes, including an enzyme for decomposing urea or an enzyme foranother use, but may contain a small amount of an enzyme for anotheruse.

In addition, the adsorber 40 may include a layer of the porous bodywhich is capable of directly adsorbing uremic substances and layers ofother elements. In this case, the layers of the other elements maycontain enzymes. In this case, the “adsorber not having an enzyme”refers to the portion of the porous body layer which is capable ofdirectly adsorbing the uremic substances in the adsorber 40.

A carbon based adsorbent is an example of the porous body which iscapable of directly adsorbing a uremic substance. The carbon basedadsorbent may be, for example, an aggregate of natural products having aporous structure such as activated carbon particles, or an aggregate offormed products having a porous structure such as beads that have poreswith an average pore diameter of about 8 nm. As described above, becausethe adsorber 40 has the carbon based adsorbent, the adsorbed uremicsubstance can be easily desorbed (removed) with regenerating water.Accordingly, it is possible for the adsorber 40 to be regenerated. Here,the uremic substances include urea, creatinine, potassium, etc.

Here, the regenerating water is water that practically does not containurea. Examples of the regenerating water include: a liquid in which ureawhich is contained in utilized regenerating water has been electrolyzed;RO water; physiological saline; unused dialysate, or tap water. Tapwater is utilized after being disinfected as appropriate. Note that withrespect to the regenerating water that contains urea which is desorbedfrom the adsorber 40, the urea is removed by electrolysis as will bedescribed later. However, there are cases in which it is difficult tocompletely remove urea at this time. Therefore, there are cases in whichthe liquid, obtained by electrolyzing urea which is contained in theutilized regenerating water, contains urea at a certain concentration.In addition, basically, the lower the concentration of urea contained inthe regenerating water, the higher the regeneration ability (the abilityto desorb urea from the adsorber 40) will become.

In addition, the adsorber 40 does not have an enzyme for decomposingurea. Therefore, it is not necessary to add or exchange enzymes in orderto regenerate the activity of the enzymes that decreases accompanyingthe decomposition of urea over time. Therefore, the adsorber 40 can bemaintained in a fixed state in the dialysate circulation unit 20, andthe dialysis system 100, that is, the blood purification apparatus, canbe made compact.

The regenerating water flow unit 50 is a flow channel for causingregenerating water to flow from a regenerating water control apparatus51 to the adsorber 40. Note that the first embodiment will be describedas an example of a flow channel in which the regenerating water flowunit 50 circulates regenerating water by causing regenerating water toflow from the regenerating water control apparatus 51 to the adsorber 40and returning the regenerating water to the regenerating water controlapparatus 51. Alternatively, the regenerating water flow unit 50 may bea flow channel that causes fresh regenerating water, which is suppliedby waterworks, etc., to the adsorber 40 and then discharges theregenerating water without circulating it, to discard the regeneratingwater. That is, the regenerating water flow unit 50 may be a flowchannel that causes regenerating water to flow to the adsorber 40without passing through the regenerating water control apparatus 51 andadditionally without circulating the regenerating water.

The regenerating water control apparatus 51 is connected to respectiveconnection switching units 41 at the upstream side of the adsorber 40(the side at which the dialysate containing the uremic substance flowsinto the adsorber 40) and the downstream side (the side at which thedialysate from which uremic substances are desorbed flows out from theadsorber 40) via regenerating water circuits 54 and 55. Note that theregenerating water circuits 54 and 55 may be equipped with secondconnection units 52 (not illustrated in FIG. 1 ; refer to FIG. 2B) whichare capable of being connected to the respective connection switchingunits 41 on the upstream side and the downstream side of the adsorber40. In addition, the regenerating water flow unit 50 is provided withfunctional units such as a regenerating water supply line, aregenerating water pump, and a drain line, as appropriate.

In addition, the regenerating water flow unit 50 is equipped with anelectrolytic tank 53 for electrolyzing desorbed urea, that is, ureawhich is contained in the utilized regenerating water that flows in theregenerating water flow unit 50. Specifically, the electrolytic tank 53stores a portion of the regenerating water that circulates in theregenerating water flow unit 50 and causes DC current to flow to aportion of the stored regenerating water in order to electrolyze urea,which is dissolved in the regenerating water by being desorbed from theadsorber 40 and is a urotoxin. Note that the electrolytic tank 53includes a gas discharge unit for discharging gas which is generated byelectrolysis.

Thereby, the adsorbed urea, which is a urotoxin, can be effectivelydissolved, so that the amount of regenerating water, which is generallyabout 18 liters, can be reduced approximately 1 liter, for example. Inaddition, the amount of regenerating water which is generally utilizedis approximately 18 liters as a result of calculating the amount whichis required when the regenerating water is caused to flow at a flow rateof 50 mL/min for 6 hours. In the case of the embodiment that includesthe electrolytic tank 53, it is only necessary for a priming volume(filling amount) of the adsorber 40 and the other components to besatisfied. Therefore, it is possible to reduce the volume of therequired amount of regenerating water to approximately 1 liter.

Here, as shown in the change from the state illustrated in FIG. 1A tothe state illustrated in FIG. 1B, the regenerating water flow unit 50 isconnectable to the adsorber 40. Specifically, for example, the adsorber40 is equipped with the connection switching units 41 that have thefunction of switching valves that switch the connection between theregenerating water flow unit 50 and the dialysate circulation unit 20 onthe upstream side and the downstream side of the dialysate circulationunit 20, respectively.

The connection switching units 41 cut off the connection with theregenerating water flow unit 50 when connected to the dialysatecirculation unit 20, and cut off the connection with the dialysatecirculation unit 20 when connected to the regenerating water flow unit50.

Note that the regenerating water flow unit 50 may be connectable to theconnection switching unit 41 of the adsorber 40 by the second connectionunit 52 which is provided in the regenerating water circuits 54 and 55.Thereby, the adsorber 40 can be disconnected from the dialysate circuits21 and 22 of the dialysate circulation unit 20 and connected to theregenerating water circuits 54 and 55 of the regenerating water flowsection 50 between a dialysis step and a regeneration step.

Because the regenerating water flow unit 50 is connectable to theadsorber 40 in this manner, it is possible for the regenerating waterflow unit 50 that includes the regenerating water control apparatus 51to be separated from the dialysate circulation unit 20. Therefore, asillustrated in FIG. 1A, during treatment, a space for installing theregenerating water flow unit 50 that includes the regenerating watercontrol apparatus 51 adjacent to the dialysate circulation unit 20 isunnecessary, and it is only necessary to secure a space for installingeach of the functional units which are provided in the blood circulationunit 10 and the dialysate circulation unit 20.

Accordingly, the dialysis system 100, that is, the blood purificationdevice can be made compact and can be easily installed in differentlocations.

(Method for Regenerating Adsorber)

Next, a method for regenerating the adsorber 40 that employs thedialysis system 100 of the first embodiment will be described.

The method for regenerating the adsorber 40 according to the presentembodiment can be applied to the regeneration of the adsorber 40 havingthe porous body.

(1) First, as illustrated in FIG. 1A, the first connection unit 11 ofthe blood circulation unit 10 is connected to the shunt 210 of thepatient 200, and the adsorber 40 having the porous body is connected tothe dialysate circulation unit 20. Uremic substances which are presentin a dialysate is adsorbed to the adsorber 40 (dialysis step). The firstconnection unit 11 is a component for connecting the arterial bloodcircuit 12 and the venous blood circuit 13 of the blood circulation unit10 to the shunt 210 of the patient 200, and directly pierces the shunt210 of the patient 200. The first connection unit 11 is equipped with apiercing needle (not shown), and a shunt connector (not shown) fordetachably connecting the piercing needle to the arterial blood circuit12 and the venous blood circuit 13.

Specifically, the connection between the adsorber 40 and theregenerating water flow unit 50 is switched and connected to thedialysate circulation section 20 by the connection switching section 41,and a dialysate control apparatus (not shown) is driven. By thisdialysis step, the uremic substances which are present in the blood ofthe patient 200 are adsorbed onto the adsorber 40, and the blood of thepatient 200 is purified.

(2) Next, as illustrated in FIG. 1B, the circulation unit to which theadsorber 40 is connected is switched from the dialysate circulation unit20 to the regenerating water flow unit 50 by the connection switchingunit 41. Note that the adsorber 40 may be separated from the dialysatecirculation unit 20, and then the connection switching unit 41 of theadsorber 40 may be switched to a connection with the regeneratingwaterflow unit 50 thereafter.

(3) Then, after the dialysis step, the regenerating water controlapparatus 51 is driven, and the uremic substances which are adsorbed onthe adsorber 40 are desorbed by the regenerating water that flowsthrough the regenerating water flow unit 50 (regenerating step).

This regenerating step desorbs the uremic substances which are adsorbedon the adsorber.

(4) The regenerating water that flows through the regenerating waterflow unit 50 during the regeneration step is electrolyzed.

(5) Subsequently, after the regeneration step, the adsorber 40 and theregenerating water flow unit 50 that includes the regenerating watercircuits 54 and 55 is cleansed and/or disinfected by heating, etc.(cleansing/disinfecting step). As an alternative to disinfection byheating, disinfection by a chemical solution (sodium hypochlorite,peracetic acid, etc.) may be conducted.

In the cleansing/disinfecting step, the adsorber 40 and the regeneratingwater flow unit 50 that includes the regenerating water circuits 54 and55 may be independently cleansed and/or disinfected. Thereby, theregenerating water flow unit 50 can be reused.

Further, the dialysate circulation unit 20 that includes the dialysatecircuits 21 and 22 may be cleansed and/or disinfected in thecleansing/disinfecting step in addition to the regenerating water flowunit 50. Thereby, the regenerating water stream 50 and the dialysatecirculation unit 20 can be reused.

Still further, the dialysate circulation unit 20 and the bloodcirculation unit 10 that includes the dialyzer 30, the arterial bloodcircuit 12, and the venous blood circuit 13 may be cleansed and/ordisinfected in the cleansing/disinfecting step in addition to theregenerating water flow unit 50. Thereby, the regenerating water flowunit 50, the dialysate circulation unit 20, and the blood circulationunit 10 can be reused.

(6) The adsorber 40 is connected to the dialysate circulation unit 20 toexecute the dialysis step again.

(7) The dialysis step and the regeneration step are alternatelyrepeated.

By performing the regeneration step after performing the dialysis stepin this manner, the uremic substances which are adsorbed on the adsorber40 can be desorbed and the adsorber 40 can be regenerated. Therefore, itis not necessary to separate the desorber 40 from the dialysatecirculation unit 20, the configuration of the dialysis system 100 neednot be complex, and the operation for regenerating the adsorber 40 issimplified. Further, because the adsorber 40 can be regenerated aplurality of times by repeating the dialysis step and the regeneratingstep, it is not necessary to separate the desorber 40 from the dialysatecirculation unit 20, the configuration of the dialysis system 100 neednot be complex, and the operation for regenerating the adsorber 40 issimplified.

Note that because there is a cleansing/disinfecting step between theregeneration step and the next dialysis step, not only RO water but alsoordinary water such as non-disinfected tap water may be utilized as theregenerating water. Because tap water supplied from waterworks may beutilized, there are advantages that transport is not required as in thecase that water stored in a physiological saline solution bag isutilized, and an RO water manufacturing apparatus is not required as inthe case that RO water is utilized. It is only necessary to connect thedialysis system 100 to waterworks, which is simple.

Next, a second aspect (hereinafter, referred to as “second embodiment”)will be described in detail with reference to the drawings. The secondembodiment differs from the first embodiment mainly in the point thatthe regenerating water flow unit 50 is connectable to the firstconnection unit 11. In addition, the regeneration method duringregeneration differs between the second embodiment and the firstembodiment. Descriptions of points which are the same as those of thefirst embodiment may be omitted.

FIG. 2A is a diagram for explaining a dialysis system 100 according tothe second embodiment during treatment, and FIG. 2B is a diagram forexplaining the dialysis system 100 according to the second embodimentduring regeneration.

(Dialysis System)

Similarly to the dialysis system 100 of the first embodiment, thedialysis system 100 of the second embodiment is equipped with adialysate circulation unit 20 which is connected to a blood circulationunit 10 via a dialyzer 30, an adsorber 40 (adsorption column) having aporous body, and a regenerating water flow unit 50, as illustrated inFIG. 2A and FIG. 2B.

However, more specifically, the regenerating water flow unit 50 isconnectable to the first connection unit 11, which is for connectingblood circuits 12 and 13 of a blood circulation unit 10 to a shunt 210,as shown in the change from the state which is illustrated in FIG. 2A tothe state which is illustrated in FIG. 2B. Thereby, the regeneratingwater flow unit 50 is indirectly connectable to the adsorber 40 throughthe blood circulation unit 10 that includes the first connection unit10, and a dialysate circulation unit 20. In addition, the regeneratingwater flow unit 50 is also indirectly connectable to the adsorber 40 byutilizing the first connection unit 11 for connecting to the shunt 210.Therefore, the adsorber 40 does not require a special structure, such asa connection switching unit 41 for switching between a connection withthe regenerating water flow unit 50 and a connection with the dialysatecirculation unit 20. Accordingly, the configuration of the adsorber 40can be simplified.

(Method for Regenerating Adsorber)

Next, a method for regenerating the adsorber 40 that employs thedialysis system 100 of the second embodiment will be described.

The method for regenerating the adsorber 40 according to the presentembodiment can be applied to the regeneration of the adsorber 40 havingthe porous body.

(1) First, as illustrated in FIG. 2A, the first connection unit 11 ofthe blood circulation unit 10 is connected to the shunt 210 of thepatient 200, and the adsorber 40 having the porous body is connected tothe dialysate circulation unit 20. Uremic substances which are presentin a dialysate is adsorbed to the adsorber 40 (dialysis step). in amanner similar to the method for regenerating the adsorber 40 thatemploys the dialysis system 100 of the first embodiment.

Specifically, a dialysate control apparatus (not shown), which isprovided in the dialysate circulation unit 20 to which the adsorber 40is connected, is driven. By this dialysis step, the uremic substanceswhich are present in the blood of the patient 200 are adsorbed onto theadsorber 40, and the blood of the patient 200 is purified.

(2) Next, following the dialysis step, the adsorber 40 in the dialysatecirculation unit 20 is indirectly connected to the regenerating waterflow unit 50 via the blood circulation unit 10. That is, the connectionof the first connection unit 11 for connecting with the shunt 210 isswitched to a connection with the regenerating water flow unit 50.

Specifically, the first connection unit 11 of the blood circulation unit10 is removed from the shunt 210 of the patient 200 and connected with asecond connection unit 52 of the regenerating water flow unit 50.Thereby, the adsorber 40 is indirectly connected to the regeneratingwater flow unit 50 via the dialysate circulation unit 20 and the bloodcirculation unit 10.

Here, in greater detail, blood during treatment flows in order from theshunt 210, the arterial piercing needle, the arterial blood circuit 12,the dialyzer 30, the venous blood circuit 13, the venous piercingneedle, and to the shunt 210. The shunt 210 and the arterial piercingneedle, a shunt connector between the arterial piercing needle and thearterial blood circuit 12, the arterial blood circuit 12 and thedialyzer 30, the dialyzer 30 and the venous blood circuit 13, the shuntconnector between the venous blood circuit 13 and the venous piercingneedle, and the shunt connector between the venous piercing needle andthe shunt 210 are attachable and detachable. For this reason, forexample, the arterial blood circuit 12 may be detached from the arterialpiercing needle, the venous blood circuit 13 may be detached from thevenous piercing needle, the arterial blood circuit 12 and the venousblood circuit 13 may be connected to the piercing needles, and the bloodcirculation unit. 10 may be connected to the second connection unit 52of the regenerating water flow part 50 via a shunt connector which isprovided between the piercing needles and the blood circulation unit 10.In addition, for example, the arterial piercing needle and the venouspiercing needle may be withdrawn from the shunt 210, and the arterialpiercing needle and the venous piercing needle may be directly connectedto the second connection unit 52 of the regenerating water flow unit 50.

(3) Next, following the dialysis step, a regenerating water controlapparatus 51 is driven, and uremic substances which are adsorbed on theadsorber 40 are desorbed by regenerating water that flows through theregenerating water flow unit 50 (regeneration step).

(4) The regenerating water that flows through the regenerating waterflow unit 50 during the regeneration step is electrolyzed.

(5) Subsequently, after the regeneration step, the dialysate circulationunit 20 that includes the adsorber 40, the blood circulation unit 10,and the regenerating water flow unit 50 are cleansed and/or disinfectedby heating, etc. (cleansing/disinfecting step). Note that as analternative to disinfection by heating, disinfection by a chemicalsolution (sodium hypochlorite, peracetic acid, etc.) may be conducted.Thereby, the regenerating water flow unit 50, the dialysate circulationunit 20, and the blood circulating nit 10 can be reused.

(6) The adsorber 40 is connected to the shunt 210 of the patient 200 viathe dialysate circulation unit 20 and the first connection unit 11 ofthe blood circulation unit 10 to execute the dialysis step again.

(7) The dialysis step and the regeneration step are alternatelyrepeated.

The method for regenerating the adsorber 40 according to the secondembodiment utilizes the first connection unit 11 of the bloodcirculation unit 10 in the manner described above, and therefore,compared to the method for regenerating the adsorber 40 according to thefirst embodiment, the method for regenerating the adsorber 40 accordingto the second embodiment is more effective than that of the firstembodiment, because there is no switching step for switching theconnection by the connection switching unit 41 of the adsorber 40between the connection with the regenerating water flow unit 50 and theconnection with the dialysate circulation unit 20. Therefore, theconnection switching unit 41 is not necessary in the adsorber 40, andthe operations involved in regeneration of the adsorber 40 can besimplified, and the configuration of the dialysis system 100 can besimplified.

Further, after the dialysis step is performed, by performing theregeneration step, the uremic substance adsorbed on the adsorber 40 canbe desorbed and the adsorber 40 can be regenerated. There is no need todisconnect, the dialysis system 100 can be simplified, and the operationfor regenerating the adsorber 40 is simplified. Further, because theadsorber 40 can be regenerated a plurality of times by repeating thedialysis step and the regenerating step, there is no need to separatethe adsorber 40 from the dialysate circulation unit 20, the dialysissystem 100 can be simplified, and the operation for regenerating theadsorber 40 is simplified.

According to the method for regenerating the adsorber 40, the adsorber40 which has a porous body and does not have an enzyme is regenerated.The dialysis step in which the adsorber 40 is connected to the dialysatecirculation unit 20 to adsorb uremic substances onto the adsorber 40and, after the dialysis step, the regeneration step in which the uremicsubstances which are adsorbed on the adsorber 40 are desorbed by theregenerating water that flows through the regenerating water flow unit50 are repeated. The regenerating water flow unit 50 can be spatiallyseparated during treatment. Compared particularly to a dialysis systemthat presumes that desorption of uremic substances from the adsorber 40(regeneration of the adsorber 40) is performed simultaneously duringtreatment, the dialysis system 100 can be made compact during treatment.In addition, the blood purification apparatus which is constituted bythe dialysate circulation unit 20 and the blood circulation unit 10,excluding the regenerating water flow unit 50, can be easily installedin different locations.

According to the dialysis system 100, the dialysis system 100 isequipped with the dialysate circulation unit 20 and the adsorber 40 thatis connected to the dialysate circulation unit 20 and has a porous bodyand does not have an enzyme. Because the regenerating water flow unit 50is connectable to the adsorber 40, the regenerating water flow unit 50can be spatially separated during treatment. The dialysis system 100during treatment can be made more compact compared to a dialysis systemthat presumes that desorption of the uremic substances (regeneration ofthe adsorber 40) is performed simultaneously with treatment. The bloodpurification apparatus that includes the dialysate circulation unit 20and the blood circulation unit 10, excluding the regenerating water flowunit 50, can be made compact, and the blood purification device can beeasily installed in different locations.

Next, an embodiment, in which the dialysis system 100 of the firstembodiment described above is not changed, but the method forregenerating the adsorber of the first embodiment is changed, will bedescribed as a third embodiment.

The method for regenerating the adsorber 40 according to the presentembodiment can be applied to the regeneration of the adsorber 40 havinga porous body. The regeneration method of the adsorber 40 according tothe present embodiment is different from the method for regenerating theadsorber described as the first embodiment in that thecleaning/disinfecting step after the regeneration step can be omitted orsimplified. Hereinafter, the method for regenerating the adsorber 40according to the present embodiment will be described in detail withreference to FIG. 1A and FIG. 1B again.

(1) First, in a manner similar to the method for regenerating theadsorber 40 that employs the dialysis system 100 of the first embodimentdescribed above, the first connection unit 11 of the blood circulationunit 10 is connected to the shunt 210 of the patient 200. The adsorber40 having a porous body is connected to the dialysate circulation unit20 to adsorb uremic substances in the dialysate onto the adsorber 40(dialysis step), as illustrated in FIG. 1A.

(2) Next, in a manner similar to the method for regenerating theadsorber 40 that employs the dialysis system 100 of the firstembodiment, the circulation unit to which the adsorber 40 is connectedis switched to the regenerating water flow unit 50 from the dialysatecirculation unit 20 by the connection switching unit 41, as illustratedin FIG. 1B. Note that the adsorber 40 may be separated from thedialysate circulation unit 20, and then the connection switching unit 41of the adsorber 40 may switch to the connection with the regeneratingwater flow unit 50 thereafter.

(3) Then, after the dialysis step, the regenerating water controlapparatus 51 is driven to desorb the uremic substances which areadsorbed on the adsorber 40 by the regenerating water that flows throughthe regenerating water flow unit 50 (regeneration step). At this time,in the present embodiment, water that contains chloride ions is utilizedas the regenerating water. The concentration of chloride ions is adaptedto ensure a necessary amount of the amount of hypochlorous acid to bedescribed later, and may be, for example, equal to the concentration ofchloride ions in physiological saline. Therefore, physiological salinemay be utilized as the regenerating water.

This regeneration step desorbs the uremic substance which are adsorbedon the adsorber 40.

(4) The regenerating water that flows in the regenerating water flowsection 50 during the regeneration step is electrolyzed in theelectrolytic tank 53. At this time, chloride ions which are contained inthe regenerating water are oxidized by electrodes to generatehypochlorous acid. That is, when the regenerating water is electrolyzed,urea is electrolyzed and hypochlorous acid is generated.

In the present embodiment, hypochlorous acid is generated during theregeneration step in this manner. Hypochlorous acid, as is widely known,is capable of being decomposed in aqueous solutions and can be utilizedas a disinfectant. Therefore, in the present embodiment, thehypochlorous acid in the regenerating water can function as adisinfectant. Specifically, during the regeneration step as well,because the regenerating water that contains the hypochlorous acid flowsthrough the regenerating water flow unit 50, the regenerating water flowunit 50 can be disinfected.

(5) Subsequently, after the regeneration step, the adsorber 40 and theregenerating water flow unit 50 that includes the regenerating watercircuits 54 and 55 is cleansed and/or disinfected by heating, etc.(cleansing/disinfecting step). Note that as an alternative todisinfection by heating, disinfection by a chemical solution (sodiumhypochlorite, peracetic acid, etc.) may be conducted.

In the cleansing/disinfecting step, the adsorber 40 and the regeneratingwater flow unit 50 that includes the regenerating water circuits 54 and55 may be independently cleansed and/or disinfected. Thereby, theregenerating water flow unit 50 can be reused.

However, in the present embodiment, during the regeneration step, theregenerating water flow unit 50 can be disinfected by utilizinghypochlorous acid which is generated as a byproduct when urea iselectrolyzed, as described above. Therefore, it is possible to omit orsimplify the cleansing/disinfecting step after the regenerating stepdescribed in (5).

Note that in the present embodiment as well, the dialysate circulationunit 20 that includes the dialysate circuits 21 and 22 may be cleansedand/or disinfected in the cleansing/disinfecting step in addition to theregenerating water flow unit 50. Thereby, the regenerating water stream50 and the dialysate circulation unit 20 can be reused.

Further, the dialysate circulation unit 20 and the blood circulationunit 10 that includes the dialyzer 30, the arterial blood circuit 12,and the venous blood circuit 13 may be cleansed and/or disinfected inthe cleansing/disinfecting step in addition to the regenerating waterflow unit 50. Thereby, the regenerating water flow unit 50, thedialysate circulation unit 20, and the blood circulation unit 10 can bereused.

(6) The adsorber 40 is connected to the dialysate circulation unit 20 toexecute the dialysis step again.

(7) The dialysis step and the regeneration step are alternatelyrepeated.

In this manner, the same effects as those of the first embodimentdescribed above can be obtained by the third embodiment. Further,according to the third embodiment, by utilizing water that containschloride ions as the regenerating water, it is possible to generatehypochlorous acid as a byproduct during the regeneration step when ureais electrolyzed. In addition, because the regenerating water flow unit50 can be disinfected utilizing the hypochlorous acid, it is possible toomit or simplify the cleansing/disinfecting step after the regeneratingstep (in particular, the cleansing/disinfecting step related to theregenerating water flow unit 50).

Next, an embodiment, in which the dialysis system 100 of the secondembodiment described above is not changed, but the method forregenerating the adsorber of the second embodiment is changed, will bedescribed as a fourth embodiment.

The method for regenerating the adsorber 40 according to the presentembodiment can be applied to the regeneration of the adsorber 40 havinga porous body. The regeneration method of the adsorber 40 according tothe present embodiment is different from the method for regenerating theadsorber described as the second embodiment in that thecleaning/disinfecting step after the regeneration step can be omitted orsimplified. Hereinafter, the method for regenerating the adsorber 40according to the present embodiment will be described in detail withreference to FIG. 2A and FIG. 2B again.

(1) First, in a manner similar to the method for regenerating theadsorber 40 that employs the dialysis system 100 of the secondembodiment described above, the first connection unit 11 of the bloodcirculation unit 10 is connected to the shunt 210 of the patient 200.The adsorber 40 having a porous body is connected to the dialysatecirculation unit 20 to adsorb uremic substances in the dialysate ontothe adsorber 40 (dialysis step), as illustrated in FIG. 2A.

(2) Next, in a manner similar to the method for regenerating theadsorber 40 that employs the dialysis system 100 of the secondembodiment, the adsorber 40 in the dialysate circulation unit 20 isindirectly connected to the regenerating water flow unit 50 via theblood circulation unit 10, as illustrated in FIG. 2B. That is, the firstconnection unit 11 for connecting with the shunt 210 is switched from aconnection with the shunt 210 to a connection with the regeneratingwater flow unit 50.

(3) Then, after the dialysis step, the regenerating water controlapparatus 51 is driven to desorb the uremic substances which areadsorbed on the adsorber 40 by the regenerating water that flows throughthe regenerating water flow unit 50 (regeneration step). At this time,in the present embodiment, water that contains chloride ions is utilizedas the regenerating water. The concentration of chloride ions is adaptedto ensure a necessary amount of the amount of hypochlorous acid to bedescribed later, and may be, for example, equal to the concentration ofchloride ions in physiological saline. Therefore, physiological salinemay be utilized as the regenerating water.

This regeneration step desorbs the uremic substances which are adsorbedon the adsorber 40.

(4) The regenerating water that flows in the regenerating water flowsection 50 during the regeneration step is electrolyzed in theelectrolytic tank 53. At this time, chloride ions which are contained inthe regenerating water are oxidized by electrodes to generatehypochlorous acid. With regard to this point, it is the same as the caseof the third embodiment described above.

In the present embodiment, hypochlorous acid is generated during theregeneration step in this manner. Hypochlorous acid, as is widely known,is capable of being decomposed in aqueous solutions and can be utilizedas a disinfectant. Therefore, in the present embodiment, thehypochlorous acid in the regenerating water can function as adisinfectant. Specifically, during the regeneration step as well,because the regenerating water that contains the hypochlorous acid flowsthrough the regenerating water flow unit 50, the regenerating water flowunit 50 can be disinfected.

Here, in the present embodiment, the blood circulation unit 10 isconnected to the regenerating water flow unit 50 as illustrated in FIG.2B. Therefore, the arterial blood circuit 12 and the venous bloodcircuit 13 within the blood circulation unit 10 can be disinfected bythe hypochlorous acid which is contained in the regenerating water inaddition to the regenerating water circuits 54 and 55 within theregenerating water flow unit 50. In addition, the dialyzer 30 which isconnected to the blood circulation unit 10 can also be disinfected.Further, the regenerating water that reaches the dialyzer 30 via theblood circulation unit 10 can further flow to the dialysate circulationunit 20 via the dialyzer 30. Accordingly, in the present embodiment, thedialysate circuit 21, etc. within the dialysate circulation unit 20 canbe disinfected by the hypochlorous acid which is contained in theregenerating water.

(5) Subsequently, after the regeneration step, the dialysate circulationunit 20 that includes adsorber 40, the blood circulation unit 10, andthe regenerating water flow unit 50 are cleansed and/or disinfected byheating, etc. (cleansing/disinfecting step). Note that as an alternativeto disinfection by heating, disinfection by a chemical solution (sodiumhypochlorite, peracetic acid, etc.) may be conducted. Thereby, theregenerating water flow unit 50, the dialysate circulation unit 20, andthe blood circulation unit 10 can be reused.

However, in the present embodiment, during the regeneration step, thedialysate circulation unit 20, the blood circulation unit 10, and theregenerating water flow unit 50 can be disinfected by utilizinghypochlorous acid which is generated as a byproduct when urea iselectrolyzed, as described above. Therefore, it is possible to omit orsimplify the cleansing/disinfecting step after the regenerating stepdescribed in (5).

(6) The adsorber 40 is connected to shunt 210 of the patient 200 via thedialysate circulation unit 20 and the blood circulation unit 10 toexecute the dialysis step again.

(7) The dialysis step and the regeneration step are alternatelyrepeated.

In this manner, the same effects as those of the second embodimentdescribed above can be obtained by the fourth embodiment. In addition,according to the fourth embodiment, by utilizing water that containschloride ions as the regenerating water, it is possible to generatehypochlorous acid as a byproduct during the regeneration step when ureais electrolyzed. Because the dialysate circulation unit 20, the bloodcirculation unit 10, and the regenerating water flow unit 50 can bedisinfected by utilizing the hypochlorous acid, it is possible to omitor greatly simplify the cleansing/disinfecting step after theregenerating step.

Next, the results of a test of electrolyzing urea will be described withreference to FIG. 3 .

FIG. 3 is a graph that shows the results of a urea electrolysis test. InFIG. 3 , the horizontal axis represents processing time, and thevertical axis represents the concentration of urea. Temporal changeproperties in a column entrance concentration and temporal changeproperties in a column exit concentration are indicated.

The test conditions were as follows.

(1) A stock solution as the regenerating water described above was aphysiological saline solution (a 0.9% sodium chloride aqueous solution),and the amount was 1 liter.

(2) A column as a porous body of the adsorber 40 was a columnar shapehaving a diameter of 120 mm and a height of 210 mm, and filled with 2300ml of an adsorbent. In addition, the column had urea, etc. adsorbedthereon in advance by a simulated treatment (urea concentration of 75mg/dL). The direction of flow of the stock solution with respect to thecolumn was from bottom to top.

(3) Regarding the electrolytic tank 53, the material of both an anodeand a cathode was platinum coated titanium. The electrode area was 662cm² for the anode and 607 cm² for the cathode, and the applied voltagewas 5 V direct current.

(4) A tube pump was used as a regenerating water pump, and the flow ratewas 50 mL/min.

(5) The stock solution as the regenerating water passed through thecolumn, was subjected to electrolysis in the electrolytic tank 53, andwas utilized again in a circulation system to pass through the columnagain.

In FIG. 3 , the column entrance concentration is the concentration ofurea in the regenerating water immediately prior to passing through thecolumn, and the column exit concentration is the concentration of ureain the regenerating water immediately following passing through thecolumn.

As shown in FIG. 3 , the column entrance concentration decreases rapidlyafter processing is initiated. From this, it can be understood thatelectrolysis of urea is being efficiently realized. Note that theinitial value of the column entrance concentration (the value whenprocessing is initiated) is the same as the initial value of the columnexit concentration (the value when processing is initiated), and is aconcentration that substantially corresponds to the concentration ofurea which is employed in the simulated treatment (75 mg/dL). From this,it can be understood that desorption of urea from the column isinitiated immediately by the regenerating water.

From FIG. 3 , it can be understood that the column exit concentrationdecreases as the processing progresses (as the processing timeincreases). From this, it can be understood that the urea which isadsorbed on the column decreases accompanying desorption of urea fromthe column by the regenerating water passing through the column. Whenthe urea which is adsorbed on the column is substantially eliminated,the column exit concentration becomes approximately zero, and the columnentrance concentration also becomes approximately zero. In this case, ifthe processing time becomes approximately seven hours, the column exitconcentration and the column entrance concentration become approximatelyzero, and a state in which continued processing will not practicallycontribute to regeneration of the column is reached.

Here, the difference between the temporal change properties of thecolumn entrance concentration and the temporal change properties of thecolumn exit concentration corresponds to the concentration of urea whichis removed from the column. Accordingly, the temporally integrated valueof the difference between these two curves correlates to the totalamount of urea removed from the column. From the results shown in FIG. 3, when the total amount of urea removed from the column was calculated,it almost coincided with the total amount of urea which was adsorbed onthe column. Therefore, substantially all of the urea which was adsorbedon the column was removed, and it was confirmed that the column wasregenerated. That is, the effectiveness of the embodiment describedabove was confirmed.

Embodiments were described in detail above. However, the presentdisclosure is not limited to any specific embodiments, and variouschange and modifications are possible within the scopes which arerecited in the claims. In addition, it is also possible to entirely orpartially combine the constituent elements of the embodiments which aredescribed above.

1. A dialysis system, comprising: a dialysate circulation unit; anadsorber which is connected to the dialysate circulation unit, having aporous body and not having an enzyme; and a regenerating water flowunit, wherein the regenerating water flow unit comprises: anelectrolytic tank for electrolyzing urea which is contained inregenerating water that flows in the regenerating water flow unit, and aregenerating water control apparatus that returns the regenerating waterto the adsorber after passing the electrolytic tank to circulate in theregenerating water flow unit, and wherein the regenerating water flowunit is connectable to the adsorber.
 2. A dialysis system as defined inclaim 1, wherein: the regenerating water flow unit is connectable to afirst connection unit for connecting a blood circuit of a bloodcirculation unit to a shunt.
 3. A dialysis system as defined in claim 1,further comprising: a connection switching unit that switches aconnection of the adsorber with either of the dialysate circulation unitand the regenerating water flow unit, wherein the regenerating waterflow unit includes a connection unit which is capable of being connectedto the connection switching unit, and is connectable to the adsorber.